The present invention relates to a component holder for testing electronic components, a component holder system comprising a component holder and an adapter to adapt to testing devices, and a testing system having a component holder, an adapter and testing devices.
Electronic components such as ICs, for example processors or memories, and also further circuits such as ASICs, are subjected to thorough tests for their use in order to ensure their serviceability. The tests are intended to test various electronic functionalities and to check the serviceability of the components under various environmental conditions as well. To this end, the components are usually subjected to a test which is carried out at operating speed; just like a burn-in test, in which the component is exposed to increased temperatures in order to simulate a manufacturing process. A typical test sequence for DRAM modules may have the following appearance, for example:
1. Pre burn-in test using a high-performance tester, as it is known;
2. Load burn-in boards used for the burn-in test;
3. Burn in, if appropriate again with a test during the burn-in;
4. First post burn-in test, a so-called hot test on the high performance tester;
5. Second post burn-in test, a so-called cold test on the high performance tester.
The prior art for handling the components to be tested is to insert (to load) the components for each of the above tests individually into the testing device used in each case and to remove them again after each test. This requires very awkward handling of the components and loads the connecting contacts of the components during each testing operation. In addition, for each testing device and for each component, it is necessary to provide a holder which permits the component and testing device to be connected mechanically and electrically. The number of necessary different component holders is therefore equal to the product of the testing devices used and the different components to be tested, or, respectively, the different number of packages for the components.
A further drawback in the individual tests of the components is to be seen in the fact that components can be interchanged when being sorted, which can lead to so-called xe2x80x9cmixed devicesxe2x80x9d. Such mistakes are extremely disadvantageous for subsequent processing and/or testing steps and, at present, can be corrected virtually only by hand.
In order to reduce the above disadvantages, it has been proposed to carry out the tests with components which remain in the transport pallets (so-called trays) provided for them. Apart from the comprehensive changes which are necessary on the testing devices in order to carry out this method, the component contacts are also loaded during each testing step in this case.
A further proposal consists in testing the components while they are still present in coherent strips. During assembly, integrated circuits are fitted to a carrier, from which at the same time the electrical contacts also branch. This carrier in each case contains eight holding positions for integrated circuits and is referred to as a strip. Part of the strip is the so-called lead frame, which surrounds the component carrier as a mechanical stabilizing means. After they have been finished, the individual components are then separated from the strip.
However, in the case of testing the components while they are still integrated in the strip, leads to the disadvantage that the separation and the shaping of the component (for example bending over the contact pins) are carried out only after the main test, so that a final functional test, including the handling need for this, still remains necessary.
The invention is therefore based on the object of simplifying the testing of electronic components without increasing the loading on the components, in particular at their contact surfaces.
According to the invention, this object is achieved by providing a component holder according to the independent patent claim 1, a component holder system according to the independent patent claim 15 and a testing system according to the independent patent claim 16. Further advantageous refinements, aspects and details of the present invention emerge from the dependent patent claims, the description and the appended drawing.
The invention is therefore directed to a component holder for testing electronic components, having a carrier, at least one component socket arranged on the carrier and having a group of component contacts to hold and make contact with a component, and at least one group of adapter contacts, which are arranged on the carrier in a predefined standard arrangement and are connected to the component contacts.
The principle on which the invention is based includes the use of adapters, which make it possible to couple any desired components to any desired testing devices, it being possible for the components to remain in a component holder, such an adapter, during all the tests and transport measures. The component holder, designed specifically for testing purposes, permits optimum adaptation to the necessities of the testing environment. One or more component sockets are arranged on a carrier. These sockets can be chosen in accordance with the design of the components to be tested and the electrical values to be complied with.
The component holder has at least one group of adapter contacts, which are connected to the contacts in the component socket and which serve to route the electrical signals and inputs away to a testing device. In this case, in principle two arrangements are possible, namely, firstly, the preferred embodiment, in which each group of component contacts is connected to its own group of adapter contacts and, secondly, the preferred embodiment in which all the groups of component contacts can be connected individually to a group of adapter contacts. The first of these two preferred embodiments has the advantage that no electronic or electrical wiring has to be carried out within the component holder, since all the contacts of all the components can be tapped off via the adapter contacts.
In contrast, the second preferred embodiment has the advantage that the component holder has to be placed on the testing device only once, and all the components can be tested one after another by switching over the contacts from one component socket to the next component socket. In this case, however, attention must be paid to the fact that the switching and circuit element used for the changeover operation to connect the component contacts to the adapter contact also have to be designed in such a way that they also satisfy, in the long term, the requirements placed on the component holder with regard to the ability to withstand temperature, etc.
The carrier can be a simple board, such as familiar to those skilled in the art as a circuit board.
In this case, a particularly simple embodiment constitutes arranging the at least one component socket and the adapter contacts on opposite surfaces of the board.
As already mentioned, it is preferred for a whole series of component sockets to be arranged on the carrier, not just a single component socket. For example, eight to 265 components would be typical, which can be accommodated jointly on a component holder, even more components being possible.
The component sockets are preferably DC isolated from one another.
As already mentioned above, the component holder must fulfill requirements on its stability during the tests. It is therefore preferred for the component holder to be so heat-resistant that it can withstand a temperature at which burn-in tests are carried out. Materials and processes for selecting the component socket, carrier and contacts which fulfill these requirements are familiar to those skilled in the art.
Furthermore, the component holder should preferably be designed to be vibration-proof, so that a secure contact with the components held in it is also ensured during burn-in tests. The ovens used for burn-in tests are operated with hot air, which is blown into the interior of the oven by vibrating fans. As a result, vibration phenomena occur in the entire oven. Reliable test results can be achieved in burn-in tests only if the components are held so firmly, or the component holder is connected so firmly to an adapter or the testing device that a reliable electrical contact is ensured.
Furthermore, the component holder can be designed in such a way that it is suitable for operation at the frequencies at which the components to be tested are operated in accordance with their specification. Components are designed for specific speed ranges of a clocking means, at least if they are digital components. Using specific preliminary tests, a decision is made during production as to what upper limit for the frequency load capacity a specific component may have. Reliable tests relating to the function of such a component may be obtained only if high-speed tests are carried out at the speed to be expected later. Therefore, the component holders according to the invention should also be designed appropriately. In particular, depending on the test used, the contacts should be low-resistant contacts, and also have a low inductance and a low capacitance. One important property for high-frequency suitability is that no jumps can occur in the impedance at the contacts.
In order also to ensure the mechanical functionality of the component holder, it is, moreover, preferred that it has devices with which it can be held and, incidentally, transported in at least one testing device. The obvious thing for this purpose in the simplest case is sufficiently wide edges of the carrier board, in which the gripping and holding mechanisms can engage. Other holder and transporting techniques, for example via incorporated magnets, etc., can also be imagined.
In order, even in a continuous production process with a high degree of automation, to be able to detect which components are on a specific component holder, and therefore to be able to start a corresponding testing program, it is further preferred for the component holder to have an encoding means which identifies the type of components which can be accommodated or are accommodated in the component holder. Such an encoding means can, for example, be an electronic device whose content can be read out. However, it can also be a device which operates optically or can be read optically, for example a light-emitting unit or a pattern of holes, executed in accordance with specific criteria, with different perforation depending on the type, which can be read with the aid of photocells.
The invention is additionally directed to a component holder system for use with testing devices for testing electronic components, the testing devices having a group of test adapter contacts, with at least one component holder according to the invention and one adapter for each of the testing devices with which the component holder system is to be used, the adapter having a group of component holder contacts in standard arrangement for making contact with at least one group of adapter contacts on the at least one component holder, and a group of testing device contacts, which are arranged in such a way that they can or do make contact with the test adapter contacts of a specific testing device, the testing device contacts being connected to the component holder contacts.
While, during the straightforward use of the component holder according to the invention, the testing devices would further have to be standardized with regard to their contacts, the use of additional adapters between component holder and testing device permits complete freedom in the choice of the testing device. As a result of the standard configuration of the adapter contacts of the component holder, on the one hand, and of the component holder contacts of the adapter, on the other hand, a uniform interface is provided. All the component holders therefore have to be designed in a standard way with regard to their corresponding adapter interface, just as all the adapters have to be designed in a standard way with regard to the component holder receptacle. The adaptation to individual components is performed by the component holder, the adaptation to individual testing devices is performed by the adapter.
If there are a number of groups of adapter contacts in standard configuration on one component holder, it is simply possible to reposition the component holder by one position in each case after a test, so that the adapter, and therefore also the testing device, comes into electrical contact with the next component.
It is likewise possible for the component holder to have a multiplicity of groups of adapter contacts, for the adapter to have the same multiplicity of groups of component holder contacts in the same arrangement as the adapter contacts; and for all the groups of component holder contacts to be connected to the group of testing device contacts. In this way, the distribution of electrical signals can be carried out in the adapter, which for this purpose must be provided with corresponding changeover devices. By means of this embodiment, the mechanical re-placement of the component holder on the adapter can be avoided.
In this case, the term xe2x80x9cstandard arrangementxe2x80x9d of the groups of contacts is to be understood in such a way that at least those groups of adapter contacts which are connected to the same group of component holder contacts must be the same in all component holder types. On the other hand, the arrangements of the groups on a component holder can differ from one another, as long as it is ensured that the corresponding groups of groups on the adapter each have the respective same arrangement.
The standard arrangement of the contacts should be designed in such a way that the number of possible connections corresponds at least to the maximum number of contacts of those components envisaged for tests which have the most connections to the outside, in order to be able to test these as well. The spatial arrangement of the individual contacts of the standard configuration should be designed in such a way that at all the test frequencies and currents or voltages, etc., which may possibly occur, the contacts permit reliable transmission of the respective signals. Appropriate contact arrangements are familiar to those skilled in the art. In addition, with regard to the selection of the contact elements used here, recourse can be made to the relevant specialist knowledge of those skilled in the art in this field. For example, the use of point-like contacts, plugs or spring pins is possible.
The invention is finally also directed to a complete testing system for testing electronic components, which has: at least one component holder according to the invention, at least one testing device for testing the electrical properties of the at least one component, with a group of test adapter contacts, an adapter for each of the testing devices with which the component holder system is to be used, the adapter having a group of component holder contacts in standard arrangement for making contact with at least one group of adapter contacts on the at least one component holder, and a group of testing device contacts which are arranged in such a way that they can or do make contact with the test adapter contacts of a specific testing device, and which are connected to the component holder contacts.
All the statements made above with regard to the component holder system of course also apply to the complete testing system, which likewise comprises the testing device. Preferably, at least one of the testing devices is a testing device suitable for testing during a burn-in test. In addition, at least one of the testing devices can preferably carry out testing at frequencies at which the components to be tested are operated in accordance with their specification, as already mentioned above.
By means of the devices according to the invention, the mechanical loading of the components is minimized, since the latter have to be loaded into a component holder only once and remain therein for all the tests. The component holders are distinguished by a simple construction and therefore low production costs. Testing devices conventionally used can continue to be used, given the use of a suitable adapter, so that no re-equipment or new purchasing costs arise.